mcp-swing-17

mcp-swing-17

MCP server and Java agent for automating Swing and JavaFX desktop applications, built for Java 17. Fork of Swing MCP.

• Version: 1.5.0-java17
• Upstream commit: abfacfa
• License: MIT (see LICENSE)
• Usage guide: USAGE.md

Contents

dist/mcp-swing-17-server.jar    MCP server (stdio)

dist/mcp-swing-17-agent.jar Java agent loaded into the target JVM dist/*.mcpb MCPB bundle for one-click clients build.ps1 Windows build (JDK 17) build.sh Linux/macOS build mcp-swing-17-server/ server sources mcp-swing-17-agent/ agent sources mcp-swing-17-common/ shared classes

Build

powershell -NoProfile -ExecutionPolicy Bypass -File build.ps1

Requires JDK 17. Maven 3.9.9 is downloaded into .build/ on first use.

On Linux/macOS:

./build.sh

or:

mvn -s maven-settings.xml -DskipTests package

Run

SWING_MCP_AGENT_JAR=<path>/dist/mcp-swing-17-agent.jar

java -jar /dist/mcp-swing-17-server.jar

The server uses stdio and is normally started by an MCP client. The agent attaches to an already running Java application by PID through attach_to_app.

{

"mcpServers": { "mcp-swing-17": { "command": "java", "args": ["-jar", " /dist/mcp-swing-17-server.jar"], "env": { "SWING_MCP_AGENT_JAR": " /dist/mcp-swing-17-agent.jar" } } } }

Differences from upstream

1. Java 17 instead of Java 21: virtual threads replaced with a regular executor.
2. Removed the Java 17-incompatible JMenu instanceof JMenuItem pattern.
3. Replaced List.getFirst() with get(0).
4. Relocated the agent's Jackson package so the target application's Jackson cannot shadow it.
5. java.version=17, JavaFX 17.
6. Real-mouse robot input is disabled by default.
7. close_window closes only the focused dialog unless a windowIndex is passed explicitly.

Security

• the agent listens on loopback only;
• keep evaluate_java disabled;
• use as a development/testing tool;
• do not expose the agent port or the response-file token.